Described in [1], signal handlers running in a vfork child have
opportunities to corrupt the parent's state. Address this by adding a new
rfork(2) flag, RFSPAWN, that has vfork(2) semantics but also resets signal
handlers in the child during creation.
x86 uses rfork_thread(3) instead of a direct rfork(2) because rfork with
RFMEM/RFSPAWN cannot work when the return address is stored on the stack --
further information about this problem is described under RFMEM in the
rfork(2) man page.
Addressing this has been identified as a prerequisite to using posix_spawn
in subprocess on FreeBSD [2].
[1] https://ewontfix.com/7/
[2] https://bugs.python.org/issue35823
Reviewed by: jilles, kib
Differential Revision: https://reviews.freebsd.org/D19058
When RFSPAWN is passed, rfork exhibits vfork(2) semantics but also resets
signal handlers in the child during creation to avoid a point of corruption
of parent state from the child.
This flag will be used by posix_spawn(3) to handle potential signal issues.
Reviewed by: jilles, kib
Differential Revision: https://reviews.freebsd.org/D19058
C/C++) in exp(3), expf(3), expm1(3) and expm1f(3) during intermediate
computations that compute the IEEE-754 bit pattern for |2**k| for
integer |k|.
The implementations of exp(3), expf(3), expm1(3) and expm1f(3) need to
compute IEEE-754 bit patterns for 2**k in certain places. (k is an
integer and 2**k is exactly representable in IEEE-754.)
Currently they do things like 0x3FF0'0000+(k<<20), which is to say they
take the bit pattern representing 1 and then add directly to the
exponent field to get the desired power of two. This is fine when k is
non-negative.
But when k<0 (and certain classes of input trigger this), this
left-shifts a negative number -- an operation with undefined behavior in
C and C++.
The desired semantics can be achieved by instead adding the
possibly-negative k to the IEEE-754 exponent bias to get the desired
exponent field, _then_ shifting that into its proper overall position.
(Note that in case of s_expm1.c and s_expm1f.c, there are SET_HIGH_WORD
and SET_FLOAT_WORD uses further down in each of these files that perform
shift operations involving k, but by these points k's range has been
restricted to 2 < k <= 56, and the shift operations under those
circumstances can't do anything that would be UB.)
Submitted by: Jeff Walden, https://github.com/jswalden
Obtained from: https://github.com/freebsd/freebsd/pull/411
Obtained from: https://github.com/freebsd/freebsd/pull/412
MFC after: 3 days
properly nested and warns about recursive entrances. Unlike with locks,
there is nothing fundamentally wrong with such use, the intent of tracer
is to help to review complex epoch-protected code paths, and we mean the
network stack here.
Reviewed by: hselasky
Sponsored by: Netflix
Pull Request: https://reviews.freebsd.org/D21610
memfd_create is effectively a SHM_ANON shm_open(2) mapping with optional
CLOEXEC and file sealing support. This is used by some mesa parts, some
linux libs, and qemu can also take advantage of it and uses the sealing to
prevent resizing the region.
This reimplements shm_open in terms of shm_open2(2) at the same time.
shm_open(2) will be moved to COMPAT12 shortly.
Reviewed by: markj, kib
Differential Revision: https://reviews.freebsd.org/D21393
per thread, so that instead of repeating the same info for all threads
in proc, it would print thread specific info. Also includes thread number
that would match 'info threads' info and can be used as argument for
thread swithcing with 'thread' command.
shm_open2 allows a little more flexibility than the original shm_open.
shm_open2 doesn't enforce CLOEXEC on its callers, and it has a separate
shmflag argument that can be expanded later. Currently the only shmflag is
to allow file sealing on the returned fd.
shm_open and memfd_create will both be implemented in libc to use this new
syscall.
__FreeBSD_version is bumped to indicate the presence.
Reviewed by: kib, markj
Differential Revision: https://reviews.freebsd.org/D21393
chflags -R on it, otherwise the command will error out. (Note that
adding -f to the chflags invocation does not help, unlike with rm.)
MFC after: 3 days
Now that flags may be set on posixshm, add an argument to kern_shm_open()
for the initial seals. To maintain past behavior where callers of
shm_open(2) are guaranteed to not have any seals applied to the fd they're
given, apply F_SEAL_SEAL for existing callers of kern_shm_open. A special
flag could be opened later for shm_open(2) to indicate that sealing should
be allowed.
We currently restrict initial seals to F_SEAL_SEAL. We cannot error out if
F_SEAL_SEAL is re-applied, as this would easily break shm_open() twice to a
shmfd that already existed. A note's been added about the assumptions we've
made here as a hint towards anyone wanting to allow other seals to be
applied at creation.
Reviewed by: kib, markj
Differential Revision: https://reviews.freebsd.org/D21392
File sealing applies protections against certain actions
(currently: write, growth, shrink) at the inode level. New fileops are added
to accommodate seals - EINVAL is returned by fcntl(2) if they are not
implemented.
Reviewed by: markj, kib
Differential Revision: https://reviews.freebsd.org/D21391
When an empty pattern is encountered in the pattern list, I had previously
broken bsdgrep to count that as a "match all" and ignore any other patterns
in the list. This commit rectifies that mistake, among others:
- The -v flag semantics were not quite right; lines matched should have been
counted differently based on whether the -v flag was set or not. procline
now definitively returns whether it's matched or not, and interpreting
that result has been kicked up a level.
- Empty patterns with the -x flag was broken similarly to empty patterns
with the -w flag. The former is a whole-line match and should be more
strict, only matching blank lines. No -x and no -w will will match the
empty string at the beginning of each line.
- The exit code with -L was broken, w.r.t. modern grep. Modern grap will
exit(0) if any file that didn't match was output, so our interpretation
was simply backwards. The new interpretation makes sense to me.
Tests updated and added to try and catch some of this.
This misbehavior was found by autoconf while fixing ports found in PR 229925
expecting either a more sane or a more GNU-like sed.
MFC after: 1 week
For now, just count batched page queue state operations.
vm.stats.page.queue_ops counts the number of batch entries that
successfully completed, while queue_nops counts entries that had no
effect, which occurs when the queue operation had been completed before
the batch entry was processed.
Reviewed by: alc, kib
MFC after: 1 week
Sponsored by: Intel, Netflix
Differential Revision: https://reviews.freebsd.org/D21782
bde reports (in a reply to r351700 commit mail):
This uses scasb, which was last optimal on the 8086, or perhaps the
original i386. On freefall, it is several times slower than the
naive translation of the naive C code.
Reported by: bde
Reviewed by: kib, markj
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D21785
Convert all remaining references to that field to "ref_count" and update
comments accordingly. No functional change intended.
Reviewed by: alc, kib
Sponsored by: Intel, Netflix
Differential Revision: https://reviews.freebsd.org/D21768
leaf 0x15 is not functional.
This should improve automatic TSC frequency determination on
Skylake/Kabylake/... families, where 0x15 exists but does not provide
all necessary information. SDM contains relatively strong wording
against such uses of 0x16, but Intel does not give us any other way to
obtain the frequency. Linux did the same in the commit
604dc9170f2435d27da5039a3efd757dceadc684.
Based on submission by: Neel Chauhan <neel@neelc.org>
PR: 240475
Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D21777
Check for teken.fg_color and teken.bg_color and prepare the color
attributes accordingly.
When white background is used, make it light to improve visibility.
When black background is used, make kernel messages light.
The kernel won't crash if you have a bad value and I'd rather not have
nvmecontrol know the internal details about how the nvme driver limits
the transfer size.
Add settable variables to control teken default color attributes.
The supported colors are 0-7 or basic color names:
black, red, green, brown, blue, magenta, cyan, white.
The current implementation does add some duplication which will be addressed
later.
This commit adds two new extensions to crontab, ported from OpenBSD:
- -n: suppress mail on succesful run
- -q: suppress logging of command execution
The -q option appears decades old, but -n is relatively new. The
original proposal by Job Snijder can be found here [1], and gives very
convincing reasons for inclusion in base.
This patch is a nearly identical port of OpenBSD cron for -q and -n
features. It is written to follow existing conventions and style of the
existing codebase.
Example usage:
# should only send email, but won't show up in log
* * * * * -q date
# should not send email
* * * * * -n date
# should not send email or log
* * * * * -n -q date
# should send email because of ping failure
* * * * * -n -q ping -c 1 5.5.5.5
[1]: https://marc.info/?l=openbsd-tech&m=152874866117948&w=2
PR: 237538
Submitted by: Naveen Nathan <freebsd_t.lastninja.net>
Reviewed by: bcr (manpages)
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D20046
Both IBM and Freescale programming examples presume the cmpset operands will
favor equal, and pessimize the non-equal case instead. Do the same for
atomic_cmpset_* and atomic_fcmpset_*. This slightly pessimizes the failure
case, in favor of the success case.
MFC after: 3 weeks
addition, the flags are optional, but were made to be mandatory. Set
these things, as well as santiy check the specified size.
Submitted by: Stefan Rink
PR: 240798
Since the NFS node mutex needs to change to an sx lock so it can be held when
vnode_pager_setsize() is called and the iod lock is held when the NFS node lock
is acquired, the iod mutex will need to be changed to an sx lock as well.
To simply the future commit that changes both the NFS node lock and iod lock
to sx locks, this commit replaces all mtx_lock()/mtx_unlock() calls on the
iod lock with macros.
There is no semantic change as a result of this commit.
I don't know when the future commit will happen and be MFC'd, so I have
set the MFC on this commit to one week so that it can be MFC'd at the same
time.
Suggested by: kib
MFC after: 1 week
`freebsd-update updatesready' can be used to check if there are any pending
fetched updates that can be installed.
`freebsd-update showconfig' writes freebsd-update's configuration to
stdout.
This also changes the exit code of `freebsd-update install' to 2 in case
there are no updates pending to be installed and there wasn't a fetch phase
in the same invocation. This allows scripts to tell apart these error
conditions without breaking existing jail managers.
See freebsd-update(8) for details.
PR: 240757, 240177, 229346
Reviewed by: manpages (bcr), sectam (emaste), yuripv
Differential Revision: https://reviews.freebsd.org/D21473
that instead of functions only being inside the _KERNEL and
the absence of RATELIMIT causing us to have NULL/error returning
interfaces we ended up with non-kernel getting the error path.
opps..
Doing some tests with very high interrupt rates I've noticed that one of
conditions I added in r232207 to make interrupt threads in most cases
run on local CPU never worked as expected (worked only if previous time
it was executed on some other CPU, that is quite opposite). It caused
additional CPU usage to run full CPU search and could schedule interrupt
threads to some other CPU.
This patch removes that code and instead reuses existing non-interrupt
code path with some tweaks for interrupt case:
- On SMT systems, if current thread is idle, don't look on other threads.
Even if they are busy, it may take more time to do fill search and bounce
the interrupt thread to other core then execute it locally, even sharing
CPU resources. It is other threads should migrate, not bound interrupts.
- Try hard to keep interrupt threads within LLC of their original CPU.
This improves scheduling cost and supposedly cache and memory locality.
On a test system with 72 threads doing 2.2M IOPS to NVMe this saves few
percents of CPU time while adding few percents to IOPS.
MFC after: 1 month
Sponsored by: iXsystems, Inc.
is a completely separate TCP stack (tcp_bbr.ko) that will be built only if
you add the make options WITH_EXTRA_TCP_STACKS=1 and also include the option
TCPHPTS. You can also include the RATELIMIT option if you have a NIC interface that
supports hardware pacing, BBR understands how to use such a feature.
Note that this commit also adds in a general purpose time-filter which
allows you to have a min-filter or max-filter. A filter allows you to
have a low (or high) value for some period of time and degrade slowly
to another value has time passes. You can find out the details of
BBR by looking at the original paper at:
https://queue.acm.org/detail.cfm?id=3022184
or consult many other web resources you can find on the web
referenced by "BBR congestion control". It should be noted that
BBRv1 (which this is) does tend to unfairness in cases of small
buffered paths, and it will usually get less bandwidth in the case
of large BDP paths(when competing with new-reno or cubic flows). BBR
is still an active research area and we do plan on implementing V2
of BBR to see if it is an improvement over V1.
Sponsored by: Netflix Inc.
Differential Revision: https://reviews.freebsd.org/D21582
Instead of predicting the MSI-X bar index based on the device's MAC
type, read it from the device's PCI configuration instead.
PR: 239704
Submitted by: Piotr Pietruszewski <piotr.pietruszewski@intel.com>
Reviewed by: erj@
MFC after: 3 days
Sponsored by: Intel Corporation
Differential Revision: https://reviews.freebsd.org/D21547
From Piotr:
r351152 introduced iflib_deregister() function calling
EVENTHANDLER_DEREGISTER() to unregister VLAN events. This patch removes
duplicate of EVENTHANDLER_DEREGISTER() calls placed in
iflib_device_deregister() as this function is now calling
iflib_deregister(). This is to avoid deregistering same event twice.
This patch also adds check in iflib_vlan_register() to prevent
registering VLAN while being in detach.
Patch co-authored by Krzysztof Galazka <krzysztof.galazka@intel.com>,
erj <erj@FreeBSD.org> and Jacob Keller <jacob.e.keller@intel.com>.
Signed-off-by: Piotr Pietruszewski <piotr.pietruszewski@intel.com>
Submitted by: Piotr Pietruszewski <piotr.pietruszewski@intel.com>
Reviewed by: gallatin@, erj@
MFC after: 3 days
Sponsored by: Intel Corporation
Differential Revision: https://reviews.freebsd.org/D21711
For a long time, some places in the NFS code have locked/unlocked the
NFS node lock with the macros NFSLOCKNODE()/NFSUNLOCKNODE() whereas
others have simply used mtx_lock()/mtx_unlock().
Since the NFS node mutex needs to change to an sx lock so it can be held when
vnode_pager_setsize() is called, replace all occurrences of mtx_lock/mtx_unlock
with the macros to simply making the change to an sx lock in future commit.
There is no semantic change as a result of this commit.
I am not sure if the change to an sx lock will be MFC'd soon, so I put
an MFC of 1 week on this commit so that it could be MFC'd with that commit.
Suggested by: kib
MFC after: 1 week
